Go on, admit it: The sheets you have on your bed right now are the same ones that were there this time last week... and maybe even the week before that. It's a habit most of us have fallen into at least sometimes (myself included), and one that seems harmless enough. Emphasis on seems. In fact, a lot of gross things happen when you don't change your sheets regularly, and once you learn the truth, you might be prompted to change your unhygienic ways.
The consumer site Mattress Advisor surveyed 1,000 Americans about their bedding-cleanliness beliefs and habits. Their responses were surprising (and not suitable for reading at mealtime). It seems that on average, we change our sheets only once every 24 days, and our pillowcases a day or two after that. (Isn't it just easier to get the whole bed taken care of at the same time?) Men leave their sheets on 10 days longer than women do, and single men don't swap out the bedding until nearly 45 days. While we can try to justify our habits if our sheets don't "look dirty," it's harder to understand why women wait nearly five days to wash their sheets after having sex, and men wait almost 12 days. (Yep, that's nearly two weeks of sleeping on sheets with dried... um... fluids.)
What happens to those thin cloths that stand between our bodies and the mattress might surprise you. What health risks they pose might make you queasy. Either way, you'll probably want to strip your bed and head for the washing machine right after you read this. (I did.)